Money talks. Companies listen when millions of customers boycott their products and services.

Peaceful, economic mass-protests aren’t new. Gandhi and Martin Luther Kings Jr. used them. Activists launch bigger, more effective protests using social media and online commerce. The purchasing power of millions of followers’ becomes a powerful tool to demand change.

How are such campaigns organized? When do they work best? What technology is involved?

BackgroundGroups with little political power have to use what few means they do have to make their voices heard. Collectively refusing to buy certain products ensures that their message is heard by corporations and relayed to politicians. Economic boycotts work.

Mahatma Gandhi is credited with organizing the first major mass economic boycott. India used to be major producer of cotton textiles before being colonized by the British. The East India Company imposed tariffs on Indian textile manufacturing, forcing cotton to be exported to the UK where it was manufactured into cloth and sold back to India. This devastated the local Indian economy. Gandhi recognized the injustice and came up with a simple, peaceful plan. He encouraged his followers to spin their own cotton yarn on a simple loom to make their own clothes. The protest worked and the British tariffs were removed.

1968 protests in MemphisSeven hundred sanitation workers went on strike in Memphis in 1968 following years of poor pay and dangerous working conditions. Memphis's mayor, Henry Loeb, declared the strike illegal and refused to meet with local black leaders. 10,000 tons of rubbish had piled up by February and Loeb began to hire strikebreakers. The marchers faced police brutality in the forms of mace, tear gas, and billy clubs. The local news media were generally favorable to Loeb, portraying union leaders as meddling outsiders.

Martin Luther King Jr (MLK) became involved. He used non-violent techniques to protest the unjust treatment of the sanitation workers developed a simple, peaceful approach to resolve the strike. The mayor may not respond to the black protestors but he would listen to his corporate supporters. MLK’s appeal to the community was simple : stop buying Wonder Bread till the firm agreed to support their civil justice demands. “We don't need no molotov cocktails. We just need to go back to these stores, and to these massive industries in our country, and say 'God sent us by here. To say to you that you're not treating His children right."

Demanding change with collective actionSupporters are organized to take action via social media. Calls to action can be quickly prepared and widely broadcast. Advocacy groups support the campaign by encouraging members to join the collective action. The campaign is amplified as supporters share the message across their social networks. Followers are directed to an online resource (such as Google Docs) that lists firms to take action against.

Pressure on retailersShannon Coulter is a founder of Grab Your Wallet. She began a boycott through a tweet with a list of companies that sold Trump products. Thousands of people contacted stores on the boycott list and many backed away from products connected to Ms. Trump. Here’s how the campaign was rolled out over Twitter, FaceBook.

Refusing to use a serviceUber was targeted for its alleged relation to Executive Order 13769 (also referred to as "Muslim ban"). As taxi drivers to JFK Airport went on strike in solidarity with Muslim refugees, Uber removed surge pricing to the airport where Muslim refugees had been detained upon entry. A social media campaign called #deleteuber arose and approximately 200,000 users deleted the app. The lifetime value of an Uber customer has been calculated as $47,000. This implies that the cost of the protest to Uber could be over $10m.

Reducing advertising supportAdvertising revenue is especially vulnerable to activism. Activists recently launched a campaign against the advertisers on the Bill O’Reilly show after the New York Times reported multiple harassment settlements. Advertisers are easily identified and listed publicly along with the action that followers should take. SleepingGiant’s Twitter campaign has over 80,000 followers and another 25,000 follow it on Facebook. Many advertisers respond to their customers requests and have stopped advertising. CNN reports that the campaign is having an impact.

MLK last speech in Memphis almost fifty years ago, presaged today’s online protests. “Always anchor our external direct action with the power of economic withdrawal. We are poor. Never stop and forget that collectively we are richer than all the nations in the world… That's power right there, if we know how to pool it”.

Technology enabled activists have figured out how.

This article is published as part of the IDG Contributor Network. Want to Join?

Deepak Puri has held executive positions at Oracle, Netscape and VMware. He is the founder of SkilledAnalysts.com, an IoT consulting firm, and co-founder of Democracy Labs, a non-profit hub in San Francisco that connects technical volunteers with progressive causes. He also serves on the board of the Tides Foundation.